[Pixman] Help with sending patch

Siarhei Siamashka siarhei.siamashka at gmail.com
Fri May 22 12:41:19 PDT 2015

On Fri, 22 May 2015 13:22:10 -0300
Fernando Seiti Furusato <ferseiti at linux.vnet.ibm.com> wrote:

> Hello!
> I work with package porting to ppc64le and I am currently working on pixman.
> Although the package compiles on the aforementioned architecture, the tests
> fail.

Hello. Thanks for contacting us. This issue looks very much like


At that time it was not very clear whether such hardware really existed
in the hands of the end users. And the reporter did not seem to be very
much interested in resolving it.

> That is actually caused by some endianness differences in vmx/altivec usage.

I guess, it makes sense. The VMX/Altivec code was written with big
endian assumptions, because nobody expected little endian PPC hardware
to exist. The generic C code paths in pixman are endian agnostic.

> Therefore, I have created a patch that works around those differences.

That's awesome. It is definitely much better than just disabling the
Altivec code path.

> What should be the best way to send that patch?

This is explained in the 'Contributing' and 'Sending patches'
sections of


It may take a bit of time to get familiar with this if you have no
prior experience with git. But on a positive side, many other open
source projects handle patches in the same way, so it's a generally
useful knowledge.

> Can I send it directly to this list?


> I appreciate any help on this.

Also before you send the patch, please pay special attention to making
sure that the Altivec code still works correctly (passes the 'make
check' test) with all the PPC flavours (big and little endian, 32-bit
and 64-bit mode). And please mention this in the commit message.


Best regards,
Siarhei Siamashka

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